From MY quick start guide "You can send a note to communicate silently with other Rino users on the same channel and code that you are using. this can be a save note or a new note.
To send a note:
1. Press ENTER and hold it until the Shortcuts menu is Displayed.
2. Select the SEND NOTE option.
3. To create a new note or edit an existing note.press ENTER when the EDIT NOTE field is highlighted. Enter your note using the data entry keyboard. Select OK when complete. To use a Saved Note, select the desired note from the SAVED NOTE list and press ENTER.
4. Select SEND to send the note to all Rino users on the same channel and code that you are using. Select SAVE to save the note for future use. Select CLEAR to erase the note."
My radio is a Rino 530HCx the book covers the 520HCx also
If you are using City navigator to to navigate to the cache , make sure you change from on road mode to off road. The on road mode will only take you as close as the nearest road.
If it is the same cable I have from Garmin, I had to contact them and they emailed me a new driver for the cable. The one that came with the cable was corrupted.